Promoting “Modern” Physics in Britain 1900-40

Imogen Clarke’s dissertation urges us to examine with much greater care the terms “classical” and “modern,” that are so frequently (and perhaps too easily) used to characterize the upheaval of early twentieth century physics. Examining institutions and intellectual debates in British physics in the first decades of the twentieth century, Clarke shows that there was no stable sense, at least in this community, of what constituted classical versus modern physics. There was no clearly defined cohort of classical physicists, no consensus as to what modern physics research should look like. In her close attention to these particular terms, Clarke engages with existing scholarly work by historians including Oliver Darrigol (“The Historians’ Disagreement over the Meaning of Planck’s Quantum,” Centaurus 43 (2001), pp. 219-239) and Richard Staley (“On the Co-Creation of Classical and Modern Physics,” Isis 96 (2005), pp. 530-558) who have examined when and how the labels “classical” and “modern” were first used by particular physicists. But where Clarke’s thesis breaks interesting new ground is by following debates surrounding the new physics out into the public sphere.

Clarke opens her dissertation with a striking set of headlines from the November 7, 1919 issue of The Times proclaiming, “Revolution in Science … Newtonian Ideas Overthrown” (p. 8). The newspaper was reporting on a meeting of the Royal Society to discuss the findings of the Eddington-Dyson solar eclipse expedition, which was widely reported to have confirmed one of the predictions of Einstein’s general theory of relativity. Historians of physics have often pointed to these observations in 1919 as pivotal in the history of “modern” physics, marking the beginning of widespread international interest in relativity among both professional physicists and the wider public (Helge Kragh, Quantum Generations. Princeton: Princeton University Press, 1999, pp. 98-104). What Clarke urges us to see, however, is that these two stories, of professional and public interest, are interrelated. The journalist’s image of a revolution, of new replacing old, of Einstein versus Newton, was exciting but also potentially disruptive to the public image of physics. If Newton had been found to be wrong, then would Einstein’s universe not be overthrown eventually as well? Clarke argues that this threat to the perceived stability and epistemic authority of physics, meant that “the transition from ‘classical’ to ‘modern’ … needed to be very carefully managed if physicists were to maintain public trust in physics …” (p. 9) Her examination of the different ways in which British physicists responded to this threat, their different visions for the future of their field, and the relationship of this future to the pillars of past theories, takes us from scholarly publications out into newspapers, popular books, textbooks and museum exhibits, showing the crucial contribution of this public discourse to the shaping of a discipline.

Clarke begins her investigation in Chapter 2 with a careful map of British physics in the early twentieth century, starting in 1895 and ending in 1911. Institutionally, she finds three different research traditions flourishing at the turn of the century: Cambridge style mathematical physics, precision measurement and J.J. Thompson’s (1856-1940) Cavendish school investigating x-rays, radioactivity and the electron. She argues that, “while the work undertaken in the Cavendish, and the laboratories developed by its alumni has come to dominate our ideas of early twentieth century physics, it was not the only ‘modern’ physics on offer” (p. 31). Low temperature physics, for instance, was a new and flourishing research tradition at this time. Following recent consensus, Clarke agrees that there was no stable, complete “classical” picture of the world waiting to be overthrown. And even those working in the new Cavendish research tradition, like Ernest Rutherford (1871-1937) at Manchester, continued to investigate older topics in optics, spectroscopy and thermodynamics (p. 59). Clarke chooses to end this chapter in 1911 in order to highlight her departure from a particular argument made by historian of science Richard Staley. Staley has argued that the meaning of “modern” physics stabilized at the 1911 Solvay Congress when it was equated with “quantum physics” by Max Planck (1858-1947). Clarke, on the other hand, argues that this is not applicable to the British case, where “1911 did not mark a moment of common understanding of the nature and purpose of ‘modern’ physics” (p. 70).

In Chapter 3, Clarke examines debates surrounding the new quantum theories, arguing that in Britain, many of the concerns revolved around a sense that quantum physics was replacing continuity with discontinuities. Debates over the ether, for instance, represented ontological debates over the existence of a continuous medium, but also questions about the proper relationship of new theories to old. Should newer theories build continuously on what came before or would older constructs be thrown out entirely? She links these questions to wider cultural preoccupations with discontinuity in art and literature, showing that of course, physics too is a cultural activity. In this chapter and the next, Oliver Lodge (1851-1940) emerges as a main character in Clarke’s story. Lodge has traditionally been cast as a classical figure who saw the ether as a crucial substance, a link between the physical and spiritual world that could not be abandoned. But Clarke argues that Lodge was just as active in shaping the discourse surrounding modern physics, and was in fact himself seen as a spokesperson for modern physics in the eyes of the public. She argues that Lodge’s defense of the ether was, in a way, both conservative and progressive at the same time: he did not want to prematurely limit the scope of physics (by saying that physicists should not investigate psychic and spiritual phenomena), but neither did he want to abandon a key tenet of physics (the ether). Overall, Lodge was deeply concerned that quantum physics sought merely to describe the world when the true aim of physics should be explanation (p. 89).

In Chapter 4, Clarke focuses again on Lodge, examining his response to Arthur Eddington (1882-1944) and to relativity theory, and analyzing Lodge’s attempts to popularize modern physics in the 1920s. Despite his persistent defense of the ether, Clarke finds that Lodge was neither ignored nor dismissed, but in fact garnered attention from both non-scientists and scientists alike. She argues that, “Lodge’s opposition to many aspects of the new physics created a perception of ‘modern’ physical theories as impermanent and unstable” (p. 106). Faced with this criticism, Arthur Eddington’s strategy was to minimize talk of revolution in order to show that relativity was a significant achievement but consistent in its physical approach with older theories. Clarke succeeds here, not only in highlighting Lodge’s role in shaping debates surrounding modern physics, but in showing that those debates took place in both popular and professional media.

In Chapters 5 and 6, Clarke continues to demonstrate the many unstable and fluid categories of modern physics in the early twentieth century. In Chapter 5, she delves more deeply into professional publications, with a close examination of the review processes of the Royal Society’s Proceedings,while in Chapter 6 she asks us to consider again the wider audience for physics, taking us to the Science Museum in London in the 1930s. In Chapter 5, Clarke shows the ways in which reviewer responses to journal submissions were wrapped up in disagreements over what constituted credible physics research while also being firmly embedded in networks of trust, with the opinions of established physicists carrying most weight. In Chapter 6, Clarke describes two very different museum exhibits offering competing visions of modern physics, one showcasing low temperature physics, and emphasizing the link to industry, and the other focusing on more abstract atomic research. Both chapters emphasize competing concepts of modern physics, but in many ways it is Chapter 6, with its focus on material culture, that is the most exciting. This is an avenue of investigation often overlooked in the history of science, and Clarke’s attention here to object history fits beautifully with her earlier analysis of print media.

Overall, Imogen Clarke’s dissertation is a welcome contribution to the history of early twentieth century physics. She has produced a nuanced picture of the culture of British physics in this time period. But even more she has amply demonstrated the rich potential of cultural histories that can weave together evidence in many forms, professional, popular and material.